JP2001239853A - Electric four-wheel drive system for vehicles - Google Patents

Abstract

(57) [Summary] An object of the present invention is to provide an electric four-wheel drive device for a vehicle that can suppress a rollback phenomenon. Another object of the present invention is to provide an electric four-wheel drive device for a vehicle that can achieve a start performance on a low μ road slope. A front wheel axle is driven by an engine, and a rear wheel axle is driven by an electric motor. When the GCU 60 detects the rollback state of the vehicle based on the output signals of the rotation sensors 56 and 58, the GCU 60 drives the electric motor to suppress the rollback state. Also, GC
When U60 detects a rollback state while the vehicle is spinning on a low μ road slope based on the output signals of the rotation sensors 56 and 58, the U60 drives the electric motor to suppress the rollback state on the low μ road slope. , Ensure the starting performance on low μ road slopes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric four-wheel drive device for a vehicle that drives four wheels of the vehicle using an engine and an electric motor.

[0002]

2. Description of the Related Art As a conventional four-wheel drive vehicle, a mechanical four-wheel drive vehicle in which all four wheels are driven by a driving force from an engine is known. By using all four wheels of the vehicle as drive wheels, it is possible to improve the traveling performance on a low μ road such as a bad road having a bad road surface or a snowy road. However, since a mechanical four-wheel drive vehicle cannot share a chassis with a two-wheel drive vehicle, for example, as described in Japanese Patent Application Laid-Open No. 7-231508, an axle driven by an engine and an electric motor are used. Electric four-wheel drive systems having separate axles to be driven have been proposed.

[0003]

However, in the conventional system described in Japanese Patent Application Laid-Open No. Hei 7-231508, when the vehicle starts on a slope, a phenomenon in which the vehicle moves backward depending on the slope of the slope (hereinafter referred to as "rollback"). "), And the driver feels fear of sudden retreat.

Further, in the system described in the conventional Japanese Patent Application Laid-Open No. Hei 7-231508, when starting on a low μ slope such as a snowy slope, the axle driven by the engine slips. Therefore, there is a problem that the starting performance on a low μ road slope cannot be obtained.

[0005] A first object of the present invention is to provide an electric four-wheel drive device for a vehicle that can suppress the rollback phenomenon.

A second object of the present invention is to provide an electric four-wheel drive device for a vehicle, which can obtain a start performance on a low μ road slope.

[0007]

(1) In order to achieve the first object, the present invention provides a vehicle having a first axle driven by an engine and a second axle driven by an electric motor. An electric four-wheel drive device for a vehicle that controls the driving of a wheel drive vehicle, further comprising control means for controlling the rollback state by driving the electric motor when the rollback state of the vehicle is detected. With such a configuration, the rollback phenomenon can be suppressed in the electric four-wheel drive vehicle.

(2) In the above (1), preferably,
A generator driven by the engine and supplying power to the electric motor, wherein the control means controls the output voltage of the generator when the rollback state is detected, thereby suppressing the rollback state It is something to do.

(3) In the above (1), preferably,
The control means detects a rollback state when the vehicle moves backward despite the fact that the driving force of the engine is transmitted to the first axle.

(4) In the above (3), preferably,
A rotation sensor for detecting a rotation direction of the axle is provided, and the control means detects, based on an output signal of the rotation sensor, that the vehicle is moving backward.

(5) In the above (3), preferably,
The control means detects that the driving force of the engine is transmitted to the first axle when the shift position is the drive range in the automatic transmission vehicle, and shifts the shift position forward in the manual transmission vehicle. Position, and detects that the driving force of the engine is transmitted to the first axle by the connection of the clutch.

(6) To achieve the second object,
The present invention provides a first axle driven by an engine;
An electric four-wheel drive device for a vehicle that drives and controls a four-wheel drive vehicle having a second axle driven by an electric motor,
When the rollback state of the vehicle on a low μ road slope is detected, a control means for driving the electric motor to suppress the rollback state is provided. With this configuration, in an electric four-wheel drive vehicle, starting performance on a low μ road slope can be obtained.

(7) In the above (6), preferably,
A generator driven by the engine and supplying electric power to the electric motor;
When a rollback state on a road slope is detected, the output voltage of the generator is controlled to suppress the rollback state.

(8) In the above (6), preferably,
The control unit is configured to control the low-μ road due to the fact that the vehicle retreats and the wheels of the first axle are spinning in spite of the driving force of the engine being transmitted to the first axle. The rollback state on a slope is detected.

(9) In the above (8), preferably,
A rotation sensor for detecting a rotation speed of the axle; the control means detects a spin based on an output signal of the rotation sensor when the rotation speed of the first axle is higher than the rotation speed of the second axle; This is to detect what is happening.

(10) In the above (6), preferably, there is provided a rotation sensor for detecting the rotation speed of the second axle, and the control means determines that the rotation speed is abrupt based on the history of the rotation speed of the second axle. As a result, the slip state of the second axle is detected, and the output of the electric motor is controlled to be suppressed.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration and operation of an electric four-wheel drive device for a vehicle according to an embodiment of the present invention will be described below with reference to FIGS. First, the overall configuration of a four-wheel drive vehicle using the electric four-wheel drive device for a vehicle according to the present embodiment will be described with reference to FIG. FIG. 1 is a system configuration diagram showing an overall configuration of a four-wheel drive vehicle using an electric four-wheel drive device for a vehicle according to one embodiment of the present invention, using FIG. 1.

The four-wheel drive vehicle 10 includes an engine 20 and a DC motor 30. The driving force of the engine 20 is
Transmission 22 and first axles 24A, 24B
Are transmitted to the front wheels 26A, 26B via the
A and 26B are driven. The driving force of the DC motor 30 is transmitted to the rear wheels 36A, 36B via the clutch 32, the differential gear 33, and the second axles 34A, 34B, and drives the rear wheels 36A, 36B. When the differential gear 33 and the clutch 32 are connected, the DC motor 3
The torque of 0 is applied to the clutch 32, the differential gear 3
3 to the rear wheel axles 34A and 34B,
A and 36B are driven. When the clutch 32 is disengaged, the DC motor 30 is mechanically disconnected from the rear wheels 36A, 36B, and the rear wheels 36A, 36B do not transmit the driving force to the road surface. The DC motor 30 uses, for example, a DC shunt motor that can easily switch between normal rotation and reverse rotation, or a separately excited DC motor.

In the above description, the front wheels 26A, 26
B is driven by the engine 20 and the rear wheels 36A and 36B are driven by the DC motor 30 as a four-wheel drive vehicle. However, the front wheels may be driven by the DC motor and the rear wheels may be driven by the engine. It is good and is also applicable to vehicles with six or more wheels such as trucks and towing vehicles such as trailers.

In the engine room, an auxiliary generator (ALT1) 40 and an auxiliary battery 42 for performing a normal charging and power generation system are arranged, and the output of the auxiliary generator 40 belt-driven by the engine 20 is output. Auxiliary battery 4
2 is stored. In the vicinity of the auxiliary generator 40,
A driving high-power generator (ALT2) 44 that is driven by the engine 20 by a belt is provided. The DC motor 30 is driven by the output of the driving high-power generator 44.
The auxiliary generator 40 is, for example, a general generator of about 12 V, 2 kW, and the driving high-output generator 44 is a generator that can obtain a higher output than the auxiliary generator 40. ,
For example, it is a generator of about 36 V and 6 kW.

The output of the engine 20 is controlled by an electronic control throttle 52 driven by a command from an engine control unit (ECU) 50. The electronic control throttle 52 is provided with an accelerator opening sensor 54 for detecting the accelerator opening. When an accelerator pedal and a throttle of a mechanical link are used instead of the electronic control throttle, an accelerator opening sensor can be provided on the accelerator pedal. The ECU 50
Controls the transmission 22. The transmission 22 is an automatic transmission, and is automatically controlled so that the gear ratio selected by the select lever 23 is achieved. The position of the select lever 23 is detected by a gear position detection sensor 25.
The transmission 22 may be a manual transmission.

The front wheels 26A, 26B and the rear wheels 36
Brakes 28A, 28 provided on the wheels A, 36B
B, 38A and 38B have anti-lock brakes (AB
S) Anti-lock brake (ABS) actuator 29A, 2 controlled by control unit 55
9B, 39A and 39B are provided. Also, front wheel 2
6A, 26B and rear wheels 36A, 36B have rotation sensors 56A, 56 for detecting rotation speed and rotation direction.
B, 58A and 58B are provided. The rotation sensors 56A, 56B, 58A, 58B are provided for each wheel, but may be arranged on one or both of the front wheel shaft and the rear wheel shaft.

Drive generator output voltage control circuit (GCU)
Reference numeral 60 denotes wheels 26A, 26B, 36A, 36B detected by the rotation sensors 56A, 56B, 58A, 58B.
Of rotation speed and rotation direction of the accelerator, accelerator opening sensor 5
4, the running state of the vehicle is determined based on the information on the accelerator opening detected by the control unit 4 and the information on the gear position detected by the gear position detection sensor 25. 44 and the DC motor 30 are controlled. Details of the control by the GCU 60 will be described later with reference to FIG.

Next, the configuration of the electric four-wheel drive device for a vehicle according to the present embodiment will be described with reference to FIG. FIG.
1 is a block diagram illustrating a configuration of an electric four-wheel drive device for a vehicle according to an embodiment of the present invention, and illustrates an example of a circuit configuration related to power supply and control. The same reference numerals as those in FIG.
The same parts are shown. In the connection between blocks in the drawing, a solid line indicates connection of power supply, and a broken line indicates connection of control.

Drive generator output voltage control circuit (GCU)
60 includes rotation sensors 56A, 56B, 58A, 58B.
26A, 26B, 36A, 36 detected by
Information on the rotation speed and rotation direction of B, information on the accelerator opening detected by the accelerator opening sensor 54, and information on the gear position detected by the gear position detection sensor 25 are input.

The GCU 60, based on these information,
The DC motor 30 is controlled by controlling the output voltage of the high-power generator 44 by outputting a command value of the output voltage to the driving high-power generator (ALT2) 44. Further, the GCU 60 directly controls the DC motor 30 by controlling a field current flowing through the field winding 31 of the DC motor 30, and the high-power generator 44.
Thus, a decrease in response caused by controlling the DC motor 30 is improved.

Drive generator output voltage control circuit (GCU)
Reference numeral 60 denotes an I / O circuit 61, an A / D converter 62, a microprocessor (MPU) 63, an I / O circuit 64,
An H-bridge driver 65 and an H-bridge circuit 66 are provided. The gear position information detected by the gear position detection sensor 25 is transmitted to the MPU 63 via the I / O circuit 61.
It is taken in. In addition, the rotation sensors 56A, 56B, 5
8A, 58B detected by the wheels 26A, 26B,
Information on the rotation speeds and rotation directions of the 36A and 36B and information on the accelerator opening detected by the accelerator opening sensor 54 are taken into the MPU 63 via the A / D converter 62. The MPU 63 includes a CPU and a memory for storing a program and data for controlling the electric motor. The MPU 63 determines a running state of the vehicle based on the input information, and calculates an output voltage value of the driving high-power generator 44. , An I / O circuit 64 to the driving high-power generator (ALT2) 44 to control an output voltage value to be generated. The MPU 63 controls the I / O so that the characteristics of the DC motor 30 conform to the required values.
The H-bridge circuit 66 adjusts the field current flowing through the field winding 31 of the DC motor 30 via the circuit 64 and the H-bridge driver 65. When the vehicle is moving backward, a field driving current is supplied from the H-bridge circuit 66 in a direction opposite to the normal rotation, so that the same backward driving force as when the vehicle is moving forward can be obtained.
Further, the MPU 63 generates an on / off signal for the clutch 32 and supplies the signal to the clutch 32 from the I / O circuit 64.

In the above description, each sensor signal is
Although it is directly input to the driving generator output voltage control circuit 60, the amount of the sensor is stored in another control unit (for example, the ECU 50 or the ABS control unit 5).
The information may be obtained from 5) via an in-vehicle LAN (CAN) bus.

The accessory battery 42 is a 12V battery, and constitutes a normal charge / discharge system between the accessory generator 40 and various electric loads for the 12V power supply. Field-side power of the DC motor 30 and the driving high-power generator 44 is supplied from the auxiliary generator 40 and the auxiliary battery 42. By providing two power supply systems, control can be performed in two ways: a method of controlling the field current of the driving high-power generator 44 and a method of controlling the field current of the DC motor 30. For example, when the required rotation speed of the electric motor is low and the required torque is high, such as when starting a vehicle,
By setting the output current value of the driving high-output generator 44 to a value that increases, the electric motor outputs low rotation and high torque. In addition, when the required rotation speed of the electric motor is high and the required torque is low when the vehicle is running, it is possible to cope with the situation by setting the output voltage value of the driving high-output generator 44 to a large value. Further, by lowering the field current of the DC motor 30, it is possible to increase the rotation speed of the motor while improving the responsiveness during running of the vehicle.

The power supply line of the clutch 32 is connected to an auxiliary battery 42. By controlling the on / off state of the clutch 32 by the MPU 63, the power generation of the driving high-power generator 44 whose power generation constantly changes. When the four-wheel drive function is not required without depending on the force, the mechanical connection between the rear wheels 36A, 36B and the DC motor 30 can be forcibly disconnected. For example, when the vehicle speed reaches 20 km / h, the clutch 32 is turned off, and the drive system for only the front wheels is used, so that the brush abrasion amount of the DC motor 30 can be reduced as compared with a system operating in the entire vehicle speed range. When the clutch 32 is disengaged, the rear wheels 36A,
36B is a driven wheel that does not generate a driving force,
A and 36B do not slip, so the rear wheel 3
The output signals of the rotation sensors 58A, 58B installed on the 6A, 36B are linked to the vehicle speed of the vehicle 10.

Next, a control method for suppressing the rollback phenomenon using the electric four-wheel drive device for a vehicle according to the present embodiment will be described with reference to FIGS. FIG. 3 is a system block diagram of a control system for suppressing a rollback phenomenon using an electric four-wheel drive device for a vehicle according to an embodiment of the present invention, and FIGS. It is explanatory drawing of the control operation | movement at the time of suppressing the rollback phenomenon using the electric four-wheel drive device for vehicles by a form. Note that FIG.
1, the same reference numerals as those in FIGS. 1 and 2 indicate the same parts.

As shown in FIG. 3, the wheels driven by the driving force of the engine 20 via the transmission 22 are, for example, front wheels 26, and the wheels driven by the DC motor 30 are rear wheels 36.

Here, the control processing contents of the GCU 60 will be described. In step s10, the GCU 60
Rotation direction, speed, and gear position detector 25 of front and rear axles input from rotation sensors 56A, 56B, 58A, 58B
The current vehicle traveling state is determined on the basis of the gear position information input from.

Here, the determination of the running state of the vehicle will be described with reference to FIGS. FIG. 4 shows a state where the vehicle is stopped by the brake.

In the driving state, both the front and rear wheels are stopped, and no driving force is transmitted to the front and rear wheels from the engine and the electric motor. Therefore, the rotation speed of the front and rear wheels is zero. The traction generated at the front and rear wheels is the drag W of the load applied to the front and rear wheels.
The sum of the values obtained by multiplying f and Wr by the static friction coefficient μ between the wheel and the road surface is generated. This traction and the retraction force applied to the center of gravity of the vehicle (the mass of the vehicle is M, the inclination angle of the slope is θ,
When the gravitational acceleration is g, M · g · sin θ) is a state in which the vehicle is stopped.
Therefore, since the rotational speeds of the front and rear axles input from the rotation sensors 56A, 56B, 58A, 58B are 0,
It can be determined that the vehicle is stationary.

FIG. 5 shows a so-called rollback state in which the vehicle moves backward. The driving force generated by the engine is applied to the front wheels. If the driving force is small, the vehicle moves backward. In the driving state, the driving force from the engine is transmitted to the front wheels, and in this state, the creep torque which is generated until the driver releases the brake and depresses the accelerator pedal is applied. No driving force is transmitted from the electric motor to the rear wheels. At this time, the traction generated by transmitting the creep torque to the front wheels (the front wheel driving force that generates the creep force) is smaller than the retreating force, and the vehicle starts to retreat. The rotational directions of the front and rear wheels are both reverse directions, and the rotational speed is the same in a region where the front wheels do not slip. Further, since there is no slip with the road surface, the vehicle speed can be estimated from the rotation speed of the wheels.

Therefore, the rotation sensors 56A, 56B, 58
A, 58B, the rotation direction of the front and rear axles is the reverse direction, the rotation speed is the same, and the gear position information input from the gear position detector 25 is the drive range (D), the vehicle running state is roll. The back state can be determined. In the case of a manual shift, the clutch is connected and the gear is in the forward direction, so that a state equivalent to the drive range in the automatic transmission is detected, and the rotational force of the engine is transmitted to the wheels. It can be determined that the vehicle is in the rollback state from the rotational direction and the rotational speed of the axle.

Next, in step s20 of FIG.
The CU 60 calculates the required motor drive torque corresponding to the traveling state determined in step s10. Next, in step s30, the GCU 60 calculates a voltage command value to the driving generator 44 so as to obtain the calculated motor driving torque, and outputs the voltage command value to the driving generator 44. The driving generator 44 internally performs feedback control so that the output voltage becomes the command value, and outputs the output voltage V to the DC motor 30. With this voltage V, the DC motor 30
Is input to the rear wheel 36, and the actual wheel speed is output, and feedback control of the entire system is performed.

For example, as shown in FIG.
Determines the rollback state, calculates the torque and the number of revolutions generated by the electric motor and outputs a command value in order to correct the rollback, so that the electric motor generates torque as shown in FIG. State. The driving state is
The driving force from the engine is transmitted to the front wheels, and this state is the creep torque that occurs between the time when the driver releases the brake and presses the accelerator pedal, or the starting torque when the accelerator pedal is depressed . A driving force output from the electric motor 30 is transmitted to the rear wheels according to a command value from the GCU 60, and a creep force or a starting force is generated as traction.

When the driver releases the brake but does not depress the accelerator pedal, the electric motor generates a driving force so that the traction generated by the transmission of the creep torque to the front wheels compensates for the shortage of the retraction force. . At this time, the GCU 60 adjusts the output of the motor by feeding back the rotation direction and speed of the front and rear wheels as needed. By such control, the vehicle stops retreating, and the vehicle moves to a stopped state. That is, by using the electric four-wheel drive device for a vehicle according to the present embodiment, it is possible to realize a hill hold function of suppressing the rollback state and bringing the vehicle to a stop state.

In a state where the driver releases the brake and further depresses the accelerator pedal, the starting mode is set, and the electric motor increases the output to apply further torque to the rear wheels. The output from the engine is also increased by depressing the accelerator pedal, and the rotation directions of the front and rear wheels are both forward directions. The controller adjusts the output of the electric motor so that the rotation speed is maintained at substantially the same speed in a region where the front and rear wheels do not slip, so that the vehicle starts.

Next, with reference to FIGS. 3 and 7 to 9, a description will be given of a control method at the time of starting on a low μ road slope using the vehicle electric four-wheel drive device according to the present embodiment. 7 to 9
FIG. 4 is an explanatory diagram of a control operation at the time of starting on a low μ road slope using the vehicle electric four-wheel drive device according to one embodiment of the present invention.

When the road surface has a low μ (friction coefficient) such as a snowy road, the wheel slips when an excessive torque is applied to the wheel. Μs (the coefficient of friction on a low μ road slope) between the road surface and the wheels changes depending on the slip ratio. Generally, μs decreases as the slip ratio increases.

In step s10 of FIG.
0 determines the current vehicle running state based on the rotation direction and speed of the front and rear axles input from the rotation sensors 56A, 56B, 58A, 58B and the gear position information input from the gear position detector 25.

When the vehicle is stopped by the brakes, the state is the same as that shown in FIG. 4 even on a low μ road hill, and the rotational speeds of the front and rear axles input from the rotation sensors 56A, 56B, 58A, 58B. Is 0,
It can be determined that the vehicle is stationary.

Next, FIG. 7 shows a state where the driver tries to start on a low μ road slope. When the driver attempts to start from the state where the brake is applied and the vehicle is stopped, the brake is released and the accelerator pedal is depressed, and excessive starting torque is applied to the front wheels due to an increase in engine output. In the case of a low μ road slope, there is not enough μs to transmit the excessive starting torque to the road surface, so that the front wheels may lose traction and enter a spin state. When the front wheels spin and the slip ratio with the road surface increases, the μs of the road surface further decreases, and the starting force, which is the traction, further decreases. At this time, the driving force of the electric motor is not transmitted to the rear wheels. When the starting force of the front wheels becomes smaller than the reversing force for retreating the vehicle, the vehicle starts retreating (rollback state). The rotation direction of the front wheel at this time is the forward direction,
The rear wheels are in the reverse direction. In addition, since the rotation speed of the front wheels is in a spin state, the rotation speed is only the rotation speed of the wheels, and is not linked to the vehicle speed. Since the rear wheels do not transmit torque, no spin occurs, and the rotation speed of the rear wheels is linked to the vehicle speed.

Therefore, the rotation sensors 56A, 56B, 58
A, 58B, the rotation direction of the front axle is the forward direction, the rotation direction of the rear axle is the reverse direction, the rotation speed of the front axle is greater than the rotation speed of the rear axle, and the gear position detector 25 If the gear position information input from the drive range is the drive range (D), it is determined that the vehicle running state has entered the spinning rollback state on a low μ road slope.

When it is determined that the vehicle is in the rollback state on the low μ road slope, the GCU 60 is determined in step s20 of FIG.
Calculates the required motor drive torque and calculates
At 30, a voltage command value for the driving generator 44 is calculated and output to the driving generator 44.

As shown in FIG. 8, when the GCU 60 determines that the vehicle is in the rollback state on the low μ road, the GCU 60 immediately activates the electric motor to generate a driving force on the rear wheels. At this time, the rotational speed of the front wheels is not linked to the vehicle speed, and if the rear wheels slip and spin, the vehicle speed cannot be determined. Therefore, control is required so that the generated torque of the electric motor does not become excessive. The vehicle speed may be determined by detecting the acceleration in the front-rear direction of the vehicle. However, since the vehicle is inclined, the DC component of the acceleration signal has an offset. Therefore, it is sufficient to detect only the AC component, but the detection sensitivity of the vehicle speed may be deteriorated.

Therefore, in the present embodiment, the history of the rotational speed of the rear wheel axle is stored in the memory, and when the rotational speed changes rapidly from the rotational speed history (when the differential component of the rotational speed increases), It is determined that the wheelset has slipped, and control is performed to suppress the output of the electric motor. Therefore, the rear wheel axle can generate the maximum driving force transmitted to the road surface, and the sum of the generated force of the front wheels and the motor assist force of the rear wheels becomes larger than the retreating force of the vehicle, and the vehicle moves forward.

FIG. 9 shows a case where the traction of the front wheels is to be recovered in the starting state shown in FIG. Since the road surface μs changes depending on the slip ratio,
If the slip ratio is reduced, the driving force transmitted to the road surface can be increased. When detecting the rollback state shown in FIG. 7, the GCU 60 recognizes the spin of the front wheel. When detecting the spin of the front wheels, the GCU 60 sends a command to the engine control unit ECU 50 to control the electronic control throttle 52 so as to suppress the output of the engine and suppress the slip of the front wheels. At this time, an electronic control throttle 52 for adjusting the output of the engine is used.
Alternatively, a command may be sent directly to the server. By performing such control, the traction of the front wheels is restored, and the vehicle can start more quickly. Instead of the throttle for controlling the intake system of the engine, a command for the brake of the front wheels may be sent to the actuator of the antilock brake mechanism or the control unit to suppress the rotation speed of the front wheels.

In the above description, a DC motor is used as the motor, but the type of the motor is not limited to a DC motor for rollback and start control of the electric four-wheel drive device for a vehicle. Alternatively, an AC motor may be used.

As described above, according to the present embodiment, the rollback phenomenon can be suppressed in an electric four-wheel drive vehicle by determining the running state of the vehicle and controlling the driving of the electric motor. In addition, by determining the running state of the vehicle and controlling the driving of the electric motor, it is possible to obtain the starting performance on a low μ road slope in an electric four-wheel drive vehicle. Furthermore, by using a rotation sensor, which is a sensor of an anti-lock brake mechanism that is widely used in general passenger cars, as a rotation sensor used to determine a vehicle traveling state, a low-cost and reliable traveling state detecting unit is provided. Can be configured.

[0054]

According to the present invention, the rollback phenomenon can be suppressed in an electric four-wheel drive vehicle. Further, according to the present invention, in an electric four-wheel drive vehicle, starting performance on a low μ road slope can be obtained.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram showing an overall configuration of a four-wheel drive vehicle using an electric four-wheel drive device for a vehicle according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of an electric four-wheel drive device for a vehicle according to an embodiment of the present invention.

FIG. 3 is a system block diagram of a control system for suppressing a rollback phenomenon using an electric four-wheel drive device for a vehicle according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram of a control operation when suppressing a rollback phenomenon using the electric four-wheel drive device for a vehicle according to one embodiment of the present invention.

FIG. 5 is an explanatory diagram of a control operation when suppressing a rollback phenomenon using the electric four-wheel drive device for a vehicle according to an embodiment of the present invention.

FIG. 6 is an explanatory diagram of a control operation when suppressing a rollback phenomenon using the electric four-wheel drive device for a vehicle according to one embodiment of the present invention.

FIG. 7 is an explanatory diagram of a control operation at the time of starting on a low μ road slope using the vehicle electric four-wheel drive device according to one embodiment of the present invention.

FIG. 8 is an explanatory diagram of a control operation at the time of starting on a low μ road slope using the vehicle electric four-wheel drive device according to one embodiment of the present invention.

FIG. 9 is an explanatory diagram of a control operation at the time of starting on a low μ road slope using the electric four-wheel drive device for a vehicle according to one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... 4 wheel drive vehicle 20 ... Engine 25 ... Gear position detector 26 ... Front wheel 28, 38 ... Brake 30 ... DC motor 31 ... Electric motor field winding 32 ... Clutch 36 ... Rear wheel 40 ... Auxiliary generator 42 ... Auxiliary battery 44 Drive high-power generator 50 Engine control unit 54 Accelerator opening sensor 55 ABS control unit 56, 58 Rotation sensor 60 Drive generator output voltage control circuit

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) F02D 29/02 F02D 29/02 D 311 311A 29/06 29/06 L 45/00 314 45/00 314M // B60K 6 / 02 B60K 9/00 E (72) Inventor Keiichi Masuno 2520 Oji Takaba, Hitachinaka City, Ibaraki Prefecture Inside the Hitachi, Ltd. Automotive Equipment Group (72) Inventor Yuji Maeda 2520 Odaikoba Hitachida City, Ibaraki Prefecture Stock Company Hitachi, Ltd. Automotive Equipment Group (72) Inventor Tateyuki Yamamoto, Oita, Hitachi, Ibaraki Prefecture, 2520 Ojiko Co., Ltd. Hitachi, Ltd. Automotive Equipment Group (72) Inventor Susumu Tajima, 2520, Oita, Hitachinaka City, Ibaraki Prefecture, Japan Hitachi, Ltd. Automotive Equipment Group (72) Inventor Naoya Shimizu 2520, Oji Koba, Hitachinaka City, Ibaraki Prefecture Hitachi, Ltd. Automotive Equipment Group (72) Inventor Keisuke Nishidate Hitachinaka City, Ibaraki Prefecture 2520 Address F-term in the Automotive Equipment Group, Hitachi, Ltd. (Reference) DA17 DA24 EA11 EB12 EB16 EB22 FA03 FA04 FA06 FA10 3G093 AA03 AA07 AA16 BA01 BA04 CB02 CB05 DB03 DB04 DB10 DB11 DB15 DB17 DB19 DB21 DB26 EA02 EA03 EB09 EC02 5H115 PA08 PG04 PI16 PI29 PI30 Q04 Q08 Q25 Q SJ12 TB01 TO01 TO02 TO04 TO21 TO30 TU20 TZ02

Claims (10)

[Claims] 1. An electric four-wheel drive device for a vehicle for driving and controlling a four-wheel drive vehicle having a first axle driven by an engine and a second axle driven by an electric motor, wherein a rollback state of the vehicle is provided. An electric four-wheel drive device for a vehicle, comprising: control means for driving the electric motor to suppress a roll-back state when the vehicle is detected. 2. The electric four-wheel drive device for a vehicle according to claim 1, further comprising a generator driven by the engine and supplying electric power to the electric motor, wherein the control means detects a rollback state. Then, the output voltage of the generator is controlled to suppress the rollback state, thereby providing an electric four-wheel drive device for a vehicle. 3. The electric four-wheel drive device for a vehicle according to claim 1, wherein the control means is configured to control the vehicle to retreat despite the engine driving force being transmitted to the first axle. An electric four-wheel drive device for a vehicle, which detects a rollback state. 4. The electric four-wheel drive device for a vehicle according to claim 3, further comprising: a rotation sensor for detecting a rotation direction of the axle, wherein the control means causes the vehicle to retreat based on an output signal of the rotation sensor. An electric four-wheel drive device for a vehicle, characterized by detecting that the vehicle is in the vehicle. 5. An electric four-wheel drive device for a vehicle according to claim 3, wherein said control means, in an automatic transmission vehicle, sets the shift position to a drive range so that the driving force of the engine is applied to the first axle. In a manual transmission vehicle, the shift position is the forward position, and it is detected that the driving force of the engine is transmitted to the first axle by the connection of the clutch. An electric four-wheel drive device for a vehicle, comprising: 6. An electric four-wheel drive device for a vehicle for controlling a four-wheel drive vehicle having a first axle driven by an engine and a second axle driven by an electric motor, comprising: When the vehicle detects the rollback state on a slope, the control means for driving the electric motor to suppress the rollback state is provided.
Wheel drive. 7. An electric four-wheel drive device for a vehicle according to claim 6, further comprising: a generator driven by said engine and supplying electric power to said electric motor, wherein said control means includes a roll on a low μ road hill. An electric four-wheel drive device for a vehicle, wherein when a back state is detected, the output voltage of the generator is controlled to suppress the roll back state. 8. The electric four-wheel drive device for a vehicle according to claim 6, wherein the control means includes means for retreating the vehicle while the driving force of the engine is transmitted to the first axle, An electric four-wheel drive device for a vehicle, wherein a rollback state on a low μ road slope is detected by spinning the wheels of the first axle. 9. The electric four-wheel drive device for a vehicle according to claim 8, further comprising: a rotation sensor for detecting a rotation speed of the axle, wherein the control means receives the first axle in accordance with an output signal of the rotation sensor. An electric four-wheel drive device for a vehicle, characterized in that when the rotation speed of the vehicle is higher than the rotation speed of the second axle, the occurrence of spin is detected. 10. The electric four-wheel drive device for a vehicle according to claim 6, further comprising: a rotation sensor for detecting a rotation speed of the second axle, wherein the control unit determines a rotation speed of the second axle based on a history of the rotation speed. An electric four-wheel drive device for a vehicle, characterized by detecting a slip state of a second axle and controlling so as to suppress the output of the electric motor when the rotational speed changes rapidly.